FEI Quanta FEG 250, User'S Operation Manual

Page: 111 / 228

Alignments: 5 - Emitter Startup
6-9
5 - Emitter Startup
This procedure enables electron source switching On / Off.
In cases of emergency shut down or the microscope mains switch off
the Ion Getter Pumps (IGP) keep pumping the FEG source area
backed up by the Battery Supply Unit (BSU). However, the main IGP
power supply is switched off at this time so it is necessary to turn it on
when the mains power is recovered.
The BSU battery provides about nine hours of uninterrupted power
when fully charged and having full capacity. If the microscope was
without the power longer than nine hours, it is usually not possible to
start the IGP´s by this alignment procedure. It is necessary to call the
service to run the bake out procedure first.